LTC1734 LINER [Linear Technology], LTC1734 Datasheet
LTC1734
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LTC1734 Summary of contents
Page 1
... SOT-23 package forms a very small, low cost charger for single cell lithium-ion batteries. The LTC1734 is available in 4.1V and 4.2V versions with 1% accuracy. Constant current is programmed using a single external resistor between the PROG pin and ground. Manual shutdown is accomplished by floating the pro- gram resistor while removing input power automatically puts the LTC1734 into a sleep mode ...
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... PROG 4.55V V 8V, Pass PNP Beta > 50 3.5V DRIVE U W INFORMATION ORDER PART NUMBER TOP VIEW LTC1734ES6-4.1 6 DRIVE LTC1734ES6-4.2 5 BAT 4 PROG S6 PART MARKING S6 PACKAGE LTHD = 230 C/W JA LTRG is equal to the float voltage unless BAT MIN TYP MAX 4. 0), 670 ...
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... Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The LTC1734E is guaranteed to meet performance specifications from ambient temperature range and 100 C junction temperature range. Specifications over the – operating ambient temperature range are assured by design, characterization and correlation with statistical process controls ...
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... LTC1734 W U TYPICAL PERFOR A CE CHARACTERISTICS I vs Temperature BAT2 and Supply Voltage 740 R = 2.15k PROG PNP = FCX589 700 V = 4.55V AND 8V CC 660 – 125 –25 100 TEMPERATURE ( C) 1734 G04 Program Pin Pull-Up Current vs Temperature and Supply Voltage 3 2.5V PROG 3 ...
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... GND (Pin 2): Ground. Provides a reference for the internal voltage regulator and a return for all internal circuits. When in the constant voltage mode, the LTC1734 will precisely regulate the voltage between the BAT and GND pins. The battery ground should connect close to the GND pin to avoid voltage drop errors ...
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... C1 initiating shutdown. . PROG For charging NiMH or NiCd batteries, the LTC1734 can function as a constant current source by grounding the BAT pin. This will prevent amplifier A1 from trying to limit charging current and only A2 will control the current. Fault conditions such as overheating of the die or exces- sive DRIVE pin current are monitored and limited ...
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... PROG pin above the PROGPU 2.15V shutdown threshold (V MSDT the charger. In this mode, the LTC1734 continues to draw some current from the supply (I SHDN gible leakage current is delivered to the battery (I Shutdown can also be accomplished by pulling the other- wise grounded end of the program resistor to a voltage greater than 2 ...
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... The program resistor value is selected by dividing the voltage forced across the resistor (1.5V) by the desired resistor current. The LTC1734 is designed for a maximum current of approximately 700mA. This translates to a maximum PROG pin current of 700 A and a minimum program resistor of approximately 2.1k. Because the PROG pin is in ...
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... PROG pin must be limited. See the Stability section for more details. Constant Current Source The LTC1734 can be used as a constant current source by disabling the voltage control loop as shown in Figure 3. This is done by pulling the BAT pin below the preset float voltages of 4 ...
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... Should the thermistor reach 125 C, the charge current will drop to 238mA and inhibit any further increase in temperature. Stability The LTC1734 contains two control loops: constant voltage and constant current. To maintain good AC stability in the ...
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... Figure 6 can be used. Figure 6. Low Loss Reverse Voltage Protection V Bypass Capacitor CC Many types of capacitors with values ranging from located close to the LTC1734 will provide adequate + input bypassing. However, caution must be exercised 6 TO Li-Ion* 20 when using multilayer ceramic capacitors. Because of the ...
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... LTC1734 U U APPLICATIONS INFORMATION resulting in the IC’s junction temperature to rise above 150 C, thus cutting off the PNP’s base current. This action will limit the PNP’s junction temperature to some temperature well above 150 C. The temperature PACKAGE DESCRIPTIO .20 (.008) DATUM ‘A’ ...